Validation of Heat-Flux Predictions on the Outer Air Seal of a Transonic Turbine Blade

Abstract

It is desirable to accurately predict the heat load on turbine hot section components within the design cycle of the engine. Thus, a set of predictions of the heat flux on the blade outer air seal of a transonic turbine is here validated with time-resolved measurements obtained in a single-stage high-pressure turbine rig. Surface pressure measurements were also obtained along the blade outer air seal, and these are also compared to three-dimensional, Reynolds-averaged Navier-Stokes predictions. A region of very high heat flux was predicted as the pressure side of the blade passed a fixed location on the blade outer air seal, but this was not measured in the experiment. The region of high heat flux was associated both with very high harmonics of the blade-passing event and a discrepancy between predicted and measured time-mean heat-flux levels. Further analysis of the predicted heat flux in light of the experimental technique employed in the test revealed that the elevated heat flux associated with passage of the pressure side might be physical. Improvements in the experimental technique are suggested for future efforts.